To put effective pressure on a corporate or political target by shutting down business as usual; to overcome the challenges of organizing vulnerable workers in isolated sectors.

One-day general strikes, like those that took place in the UK and Oakland in November 2011, are primarily symbolic protests, more focused on making a political point than creating real economic pressure. To harness the tactic’s true potential, general strikes need to escalate from symbolic one-day protests to ongoing actions that last days and potentially weeks, with a clear goal of inflicting both economic and political damage until the strikers’ demands are met.

Strikes can be a powerful weapon for shifting the balance of power in workplaces and points of production. By withholding their labor and stopping work from continuing, generations of workers over the last 150 years have won better wages, working conditions, and basic bargaining rights.

It is too easy, however, to romanticize the idea of strikes and general strikes. Due to the increasing concentration of transnational corporate power and various laws limiting workers rights, most strikes in the United States are now small and rarely successful rearguard actions to resist wage and benefit cuts. Workers need to creatively reinvent the tactic if strikes are again going to be an effective weapon to win justice. In particular, workers need to recognize, and harness, the power of general and cross-industry strikes.

The citywide general strikes of janitors in Los Angles (2000), Boston (2002) and Houston (2006) are one example of how an industry-wide general strike successfully forced powerful corporations hiding behind cleaning subcontractors to meet the demands of tens of thousands of striking janitors. Undocumented immigrant janitors were able to use sit-ins, street blockades and nonviolent civil disobedience, backed by supporters around the world, to build movements that could win. At various points, striking workers and their supporters effectively shut down business-as-usual in the business districts of the cities. The strikes, pitting poor janitors against rich landlords, won massive public support and saw the workers’ demands met.

Key to the success was the fact that striking janitors continued to escalate their tactics. Instead of just engaging in picketing at their work site, each janitor, liberated from work by the strike, became a full-time organizer, campaigning against the corporations and politicians that control and profit from the real estate industry the workers were targeting. In Los Angeles, that meant literally thousands of striker/organizers working full-time, day in and day out, organizing demonstrations that shut down streets and occupied office buildings while mobilizing community and ecumenical support.

The striking janitors learned firsthand that small, isolated strikes are rarely effective, but that going on a citywide general strike, even in large numbers, doesn’t alone lead to victory either. To win, strikers need to have a clear understanding of the target and its vulnerabilities, and develop a plan to exploit those vulnerabilities. No one action or tactic will provide enough pressure. There needs to be constant, creative and courageous escalation.

Successful workplace actions depend on choosing the right target and determining how best to apply pressure on that target. The most vulnerable target may not always be the most obvious one — the janitors had far more success in targeting the real estate companies in which they worked, rather than the shadowy subcontractors who were their direct employers, and who were far less vulnerable to public pressure and bad press.

Stephen Lerner is architect of the Justice for Janitors campaign. He serves on the executive board of the Service Employees International Union. He has been a labor and community organizer for over thirty years and is working with labor and community groups in campaigns that challenge Wall Street’s and big corporations’ domination of the political and economic life of the U.S. and global economy. His latest thinking here: How We Can Mobilize To Be the Greedy 1%'s Worst Nightmare